JPH11297028A - Magnetic tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve an inexpensive and simple configuration by providing a means for energizing a slider that is mounted to the outer, lower surface of a lower half to a closing position so that it can slide between an open position for opening a reel shaft insertion hole on the bottom surface of the lower surface and the closing position for blocking. SOLUTION: A slider spring 26 is provided with two arms 26b and 26c that consist of one wire and are extended from both ends of a torsion bar 26a to the torsion bar 26a at right angle and with a specific angle each other and have different lengths. The longer arm 26b touches a rib 14c that is provided at a slider 14, the torsion bar 26a is engaged to a slit 12f that is provided at a wall-shaped rib 12e of a lower half 12, and the shorter arm 26c touches the wall-shaped rib 12e. When the arm 26b receives a counterforce from the rib 14c, the shorter arm 26c is supported by a counterforce being received from the wall-shaped rib 12e, the arms 26b and 26c are deflected, and the torsion bar 26a is twisted, thus generating energization force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape cassette, and more particularly to a magnetic tape cassette in which a biasing means for a slider mounted on a lower half is improved.

[0002]

2. Description of the Related Art As is well known, a magnetic tape cassette such as a DDS or a DAT has a pair of take-up hubs or a pair of winding hubs each having a long magnetic tape fixed at each end and wound around the magnetic tape. The take-up reel is housed in a cassette case (cassette body composed of an upper half and a lower half joined in a lid-like manner) exposing only a portion of the magnetic tape stretched between the two hubs. Is done.
Since high-density recording is performed on the magnetic tape, it is necessary to improve the confidentiality of the case, particularly in order to prevent the fingers from contacting the magnetic tape and the attachment of dust. On the other hand, when using a cassette,
In the cassette case, there is required an insertion hole for the reel shaft and a space for inserting guides during recording / reproduction.

For this reason, a slider is provided on the outer lower surface of the lower half so as to be slidable between an open position for opening the reel insertion hole on the bottom surface of the guide insertion portion and the lower half of the cassette case and a closed position for closing. Is provided. Further, the slider is provided with a wall-shaped rib along the back side of the magnetic tape in a portion stretched between the pair of winding hubs, to prevent dust from entering the cassette case. . The slider is urged to the closed position (the front side of the cassette case) by urging means (slider spring).

FIG. 8 is a perspective exploded view showing a schematic configuration of a conventional magnetic tape cassette. The magnetic tape cassette mainly includes an upper half 90 and a lower half 91, between which a magnetic tape 93 wound around a winding hub 92 is accommodated.
On the front side of the upper half 90, a front lid 94 that covers and protects the magnetic tape when the cassette is not used is rotatably mounted around a support shaft 94a. In addition, lower half 9
A slider 95 is attached to the outer lower surface of the housing 1 so as to be slidable in the front-rear direction in order to close an open portion on the lower side of the case to enhance the airtightness.

[0005] A brake member 97 is attached to the upper half 90 to prevent the magnetic tape 93 wound around the winding hub 92 from being loosened when the cassette is not used. The brake member 97 prevents the rotation of the winding hub 92 and prevents the magnetic tape 93 from loosening by engaging the braking piece 97 a with a gear 92 a provided on the upper portion of the winding hub 92. The brake member 97 is moved by a brake spring 98.
When the cassette is not used, the brake piece 97a is urged to a position where the brake piece 97a is engaged with the gear 92a. Brake spring 98
Is locked to a projection 90 a provided on the upper half 90.

A lower half 91 is provided with a curved wall-shaped member 91 along a magnetic tape 93 wound around a winding hub 92.
a is provided, and a triangular plate member 91b is attached to the upper part thereof. The triangular plate material 91b increases the rigidity of the wall-shaped plate material 91b and the case, improves the hermeticity in the case in combination with the ribs of the upper half 90 (not shown), improves the dustproof effect, and further increases the brake spring 98. It has a role of supporting it from below and preventing it from coming off. A boss 91c is provided on the lower half 91, and a torsion coil spring 96 is locked as urging means (slider spring) for urging the slider 95 forward. Further, the slider 95 has a torsion coil spring 96.
And a rib 95a for receiving the urging force or inserting the torsion coil spring 96 is provided upright.

[0007]

However, there is still room for improvement in the above-described torsion coil spring 96 as the urging means for the slider. In other words, it is desirable to use a simpler one from the viewpoint of cost, as long as the necessary urging force can be exerted as the urging means for urging the slider. There are problems to be solved, such as troublesome positioning for accurately assembling the 96 into the boss 91c, and uneven biasing force on the slider 95 because the torsion coil spring 96 is cantilevered.

The present invention has been made in view of the above-mentioned conventional problems, and it is an object of the present invention to provide a magnetic tape cassette in which the slider urging means has been improved to a cheap and simple structure.

[0009]

According to the present invention, there is provided a cassette case for accommodating a pair of winding hubs each having a magnetic tape wound thereon, the cassette case being provided between the pair of winding hubs. The upper half and the lower half which are joined together so as to expose only the magnetic tape of the stretched portion, and the guide insertion portion on the front side of the cassette case and the reel shaft insertion hole on the bottom surface of the lower half are opened. A magnetic tape cassette comprising a slider mounted on the outer lower surface of the lower half so as to be slidable between an open position and a closed position for closing, and biasing means for biasing the slider to the closed position. So,
A magnetic tape cassette characterized in that a torsion bar is used as the urging means.

[0010] Further, the biasing means is formed of a single linear member, and extends from both ends of the torsion bar at right angles to the torsion bar and at a predetermined angle to each other.
It has two arms with different lengths, the tip of the longer arm is
It is preferable that the torsion bar be fitted into a slit of the rib provided on the lower half while being in contact with a rib provided on the slider.

Further, the biasing means is formed of a single linear member and has two torsion bars in a direction perpendicular to the bottom surface of the lower half, and the two torsion bars have one end thereof. Are connected to each other by a horizontal portion, the horizontal portion is fixed to the lower half, and an arm extending forward from the other end of each of the torsion bars to form a C-shape; It is preferable that the tip of the slider bend vertically and abut on the rib of the slider.

Further, the biasing means is formed of a single linear member, and has two torsion bars in a direction perpendicular to the bottom surface of the slider. Are connected by a horizontal portion, the horizontal portion is fixed to the front of the slider, and the arm has two arms extending rearward from the other end of the torsion bar, respectively. It is preferable that a vertex formed by the two arms is configured to abut on a boss provided on the bottom surface of the lower half at an apex angle to the vertex.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a magnetic tape cassette of the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.

FIG. 1 is an exploded perspective view showing a schematic configuration of a first embodiment of a magnetic tape cassette according to the present invention. The magnetic tape cassette is mounted slidably in the front-rear direction on the upper half 10, the lower half 12, and the lower outside of the lower half 12, which form a casing that is combined with a lid and forms a cassette case (cassette body). And a slider 14 which is configured.

A pair of take-up hubs 16 and 16 are accommodated in a cassette case composed of an upper half 10 and a lower half 12.
The magnetic tape 18 wound and stretched is accommodated. When the cassette is not used, the upper half 10 is provided with a brake member 20 so that the winding hub 16 rotates and the magnetic tape 18 does not slack. The brake member 20
It has two brake pieces 20a, 20a, and this brake piece 20a
Engages with a gear 16 a provided on the winding hub 16 to inhibit the rotation of the winding hub 16. When the cassette is not used, the brake member 20
Is biased by a brake spring 22 using a torsion coil spring so that the braking piece 20a is engaged with the gear 16a. The brake spring 22 is connected to the upper half 10
It is attached to a rib 10a provided inside. When the cassette is not used, the upper half 10 has a magnetic tape 18 stretched between the pair of winding hubs 16, 16.
A front cover 24 is provided on the front surface of the upper half 10 in order to protect the portion.

The lower half 12 has a rectangular bottom surface 12a.
And a reel shaft insertion hole 12b for inserting the reel shaft into the cassette case when the cassette is used, and a projecting portion 12 extending forward from both left and right ends of the bottom surface 12a.
c, 12c. Left and right overhang 1
2c and 12c are cylindrical tape guides 12d and 1c for guiding (guiding) a portion of the magnetic tape 18 stretched between the pair of winding hubs 16 and 16 to the front of the case.
2d is erected perpendicularly to the bottom surface 12a. The space between the left and right overhanging portions 12c, 12c is a space (guide) for a so-called tape loading device provided on the recording / reproducing device (deck) side into which the magnetic tape cassette is loaded. Insertion section).

The slider 14 is mounted on the bottom surface 12 of the lower half 12.
a, and slides in the front-rear direction of the cassette, but when it is located at the front closed position, the space between the left and right overhanging portions 12c, 12c of the lower half 12 and the reel shaft insertion hole 12b are removed. The slider 14 is closed by a bottom surface 14a for dust prevention. When the slider 14 is located at the rear open position, the left and right protrusions 12c, 12c
c and the reel shaft insertion holes 12b, 12b
Is to be released.

When the cassette is mounted on the deck, the slider 14 is automatically unlocked by the action of a device in the deck, and two sliders 14 are provided on the front side of the slider 14 by members of the device (not shown). Opening and closing ribs 14b, 14
b is pressed and positioned rearward. Also, the slider 14
When the cassette is not used, it is biased by the slider spring 26 and is positioned forward. This slider spring 26
The torsion bar 26a is used, and the lower half 1
2 is attached to a slit 12f provided in a wall-shaped rib 12e provided upright on the bottom surface. On the front side of the slider 14, a spring receiving rib 14c for hooking the arm 26b of the slider spring 26 and receiving an urging force is provided upright. When the slider 14 is located forward, the front cover 24 is arranged so as not to interfere with the opening / closing ribs 14b.
Notches 24a, 24a are provided at the positions corresponding to.

The present invention relates to a slider spring 26 using the torsion bar 26a. FIG. 2 is a plan view of the torsion bar 26a according to the first embodiment, and the lower half 12 and the slider 14 incorporating the torsion bar 26a. Show.
As shown in FIG. 2 (a), the slider spring 26 is formed of a single wire, and extends from both ends of the torsion bar 26a at right angles to the torsion bar 26a and at a predetermined angle to each other. It has two different arms 26b and 26c. Therefore, when the slider spring 26 is viewed from the side (one of the horizontal bars is long), it has a U shape. FIG.
As shown in (b), the longer arm 26b contacts the rib 14c provided on the slider 14, and the torsion bar 26a is fitted into the slit 12f provided on the wall-like rib 12e of the lower half 12. The shorter arm 26c
Is in contact with the wall-shaped rib 12e.

When the longer arm 26b receives a reaction force from the rib 14c, this reaction force is supported by the reaction force that the shorter arm 26c receives from the wall-shaped rib 12e, and
b and 26c bend, and the torsion bar 26a receives a torsion. The bending of the long arm 26b and the torsion bar 26a
Generates a biasing force on the slider 14.

According to the present embodiment, the slider spring 26
Can be made simply by simply bending the wire, the cost is low, the assembling is easy, the conveyance by an automatic machine is easy, and the torsion bar 26a is only required to be inserted into the slit 12f, which is extremely simple.

As a modification of this embodiment, as shown in FIG. 3, a coil 26d is provided in the middle of the longer arm 26b so that the arm 26b relaxes the torsion bar 26a. Is also good.

Next, a second embodiment of the present invention will be described. The slider spring of the present embodiment is "double-ended" in order to equalize the biasing force of the slider. FIG.
(A) shows the lower half 112 which receives the slider spring of this embodiment. The lower half 112 has a protruding portion 112 protruding forward from both ends of a rectangular bottom surface 112a.
c, 112c, and each overhanging portion 12c, 112c is provided with a cylindrical tape guide 112d, 112d as in the first embodiment. In the second embodiment,
The shape of the central portion of the wall-like rib 112e provided on the bottom surface 112a is different from that of the first embodiment. Wall-shaped rib 11
2e is interrupted at the center, and before that, the bottom surface 112a
Is provided with a rib 112g standing upright. This rib 1
12g corresponds to a projection for receiving a brake spring provided on the upper half, and functions to increase the rigidity of the case.

FIG. 4 shows the center of the wall-shaped rib 112e.
(B) shows an enlarged view. However, rib 1
12g is omitted. The center of the wall-shaped rib 112e is interrupted to form a column 112k. Then, a protrusion 11 for fixing the slider spring is provided in front of the column 112k.
2h are provided.

FIG. 4C shows a state where the slider spring of the present embodiment is incorporated in the lower half 112. As shown in the figure, the slider spring 126 is made of a single linear member and has two torsion bars 126a, 126a in a direction perpendicular to the bottom surface 112a of the lower half 112. These two torsion bars 126a, 126a
Are connected at one end to each other by a horizontal portion 126b, and the horizontal portion 126b is
It is fixed to the lower half by 2h. Also, arms 126c extending forward from the other ends of the torsion bars 126a, 126a so as to form a C shape,
126c, the tip 126 of the arm 126c, 126c
d and 126d are configured to bend vertically and abut a rib of a slider (not shown).

The slider spring 126 is connected to the lower half 112.
FIG. 5A is a plan view showing a state in which the slider 114 is combined with the slider 114, and FIG.
(B). As shown in FIG. 5A, the C-shaped arms 126c of the slider spring 126,
6d and 126d uniformly urge the rib 114c of the slider 114, so that the slider 114 can slide stably. In addition, although a device using a U-shaped leaf spring has been devised, the cost of the present embodiment, which is a wire, can be reduced. As shown in FIG. 5B, here, the horizontal portion 126b is disposed below and the arm 126c is disposed above, but these may be reversed upside down.

Next, a third embodiment of the present invention will be described. In the third embodiment, the bias of the slider is evened, but the slider spring is fixed to the slider. FIG. 6 shows a state where the slider spring of the present embodiment is incorporated in the slider and the lower half. FIG. 7A is a plan view, and FIG. 7B is a front view.

As shown in FIG. 6 or FIG. 7, the slider spring 226 of this embodiment is made of a single linear member, and has two torsion bars 226a, 226a perpendicular to the bottom surface 214a of the slider 214. Have. One end of the two torsion bars 226a, 226a is connected by a horizontal portion 226b. The horizontal portion 226b is fixed by protrusions 214a provided at three places in front of the slider 214. Two arms 226c, 226c extend rearward from the respective other ends of the torsion bars 226a, 226a.
A triangle is formed by c and 226c and the horizontal portion 226b. A vertex 226e formed by the two arms 226c, 226c is directed downward from a triangular plate-like member 212b provided above the wall-like rib 212a of the lower half 212 at the apex angle. It is in contact with a boss 212c formed to extend.

As in the second embodiment, this embodiment has a good balance of the urging force. Further, since the slider spring 226 is fixed to the slider 214, the slider spring 226 can be separately assembled in advance, so that the spring can be more easily incorporated. In the second and third embodiments, since the biasing force is made uniform, the sliding of the slider is stabilized, and since the stress is dispersed, the spring is sufficiently resistant to fatigue.

Although the magnetic tape cassette of the present invention has been described in detail above, the present invention is not limited to the above examples, and various improvements and changes can be made without departing from the gist of the present invention. Of course it is good.

[0031]

As described above, according to the present invention, the cost of the slider spring can be reduced by simplifying the structure of the slider spring, and the assembling of the slider spring can be facilitated. Further, when the slider spring has a U-shape or a triangular shape, the urging force can be made uniform, and stable sliding of the slider can be ensured.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a schematic configuration of a magnetic tape cassette according to the present invention.

FIG. 2A is a perspective view showing a slider spring according to the first embodiment of the present invention, and FIG. 2B is a plan view showing a lower half and a slider in which the slider spring of FIG. .

FIG. 3A is a perspective view showing another example of the slider spring of the first embodiment, and FIG. 3B is a plan view showing a lower half and a slider in which the slider spring of FIG. It is.

FIG. 4A is a perspective view showing a lower half of a second embodiment of the present invention, and FIG. 4B is an enlarged perspective view showing the vicinity of the center of the wall-shaped rib of FIG. And (c) is
It is a perspective view showing signs that the slider spring of a 2nd embodiment was assembled to (b).

FIG. 5A is a plan view showing a lower half and a slider to which the slider spring of FIG. 4C is assembled;
(B) is a front view of (a).

FIG. 6 is an enlarged perspective view showing a slider incorporating a slider spring according to a third embodiment of the present invention and a main part of a lower half.

7A is a plan view of a slider and a lower half incorporating the slider spring of FIG. 6, and FIG.
It is a front view with respect to (a).

FIG. 8 is an exploded perspective view showing a schematic configuration of a conventional magnetic tape cassette.

[Explanation of symbols]

10 Upper Half 12, 112, 212 Lower Half 12a, 112a, 212a (Lower Half) Bottom Surface 12e, 112e, 212e (Lower Half) Wall-like Member 12f Slit (Provided on Wall-like Member) 14 Slider 16 Take-up hub 16a Gear 18 Magnetic tape 20 Brake member 22 Brake spring 24 Front lid 26, 126, 226 Slider spring 26a, 126a, 226a Torsion bar 26b, 26c Arm (of slider spring) 112h (of lower half holding slider spring) Projection 114a Projection 126b (of slider to hold slider spring) 126b, 226b Horizontal portion 126c, 226c Arm (of slider spring)

Claims (2)

[Claims] 1. A cassette case accommodating a pair of winding hubs around which a magnetic tape is wound, and a lid-like shape so as to expose only a portion of the magnetic tape stretched between the pair of winding hubs. Upper and lower halves, which are slidable between an open position for opening a reel insertion hole on a bottom surface of the guide insertion portion and a bottom surface of the lower half of the cassette case, and a closed position for closing. A magnetic tape cassette comprising: a slider mounted on an outer lower surface of the lower half; and urging means for urging the slider to a closed position, wherein a torsion bar is used as the urging means. Characterized magnetic tape cassette. 2. The urging means is composed of a single linear member and has two torsion bars in a direction perpendicular to the bottom surface of the slider. Are connected by a horizontal portion, the horizontal portion is fixed to the front of the slider, and the arm has two arms extending rearward from the other end of the torsion bar, respectively. The magnetic tape cassette according to claim 1, wherein a vertex formed by the two arms is configured to abut on a boss provided on the lower half at an apex angle with respect to the two arms.